A display substrate in an organic light emitting diode (OLED) display panel includes an array of thin film transistors and an array of light emitting elements. The array of thin film transistors includes a plurality of thin film transistors. The array of light emitting elements includes an anode layer, a cathode layer and an organic functional layer between the anode layer and the cathode layer. The anode layer includes a plurality of anodes that are connected in one-to-one correspondence with drain electrodes of the thin film transistors.
The cathode layer is formed typically by sputtering transparent metal oxide such as indium tin oxide (ITO) or evaporating a partially transparent metal material over the organic functional layer.